The 6 minute walking test in chronic heart failure: indications, interpretation and limitations from a review of the literature

Prognostic utility of B-type natriuretic peptide and 6-min walk test in patients with acute decompensated heart failure

BACKGROUND

We aimed to assess the utility of B-type natriuretic peptide (BNP) and 6-min walk test (6 MWT) together as predictors of re-hospitalization and mortality in acute decompensated heart failure (ADHF) patients.

METHODS

This prospective, observational, comparative study was conducted at a tertiary care center in India between October 2016 and March 2018. Patients (aged≥18 years) with ADHF and left ventricular systolic dysfunction were included in this study. The study group (N = 100 patients) consisted of patients undergoing a second BNP test along with the 6 MWT at the time of discharge and at 3-months of discharge. The control group (N = 100 patients) consisted of patients who did not undergo these tests at discharge and/or at 3-months of discharge. Study endpoints were re-hospitalization within 6-months, and in-patient and 6-month mortality.

RESULTS

Total 200 patients diagnosed with ADHF were enrolled. Mean age was 53.46 ± 10.12 years in the study group and 52.98 ± 9.88 years in the control group. ROC analysis of BNP level to predict re-hospitalization revealed AUC of 0.935 (p < 0.001) at admission, 0.915 (p < 0.001) at discharge, and 0.783 (p < 0.001) at 3-months. Similarly, at discharge, ROC analysis of 6 MWT to predict death gave AUC of 0.670 (p = 0.011), and at 3-months, it was 0.838 (p < 0.001). ROC analysis of BNP level to predict mortality showed AUC of 0.960 (p < 0.001) at admission, 0.947 (p < 0.001) after discharge, and 0.960 (p = 0.002) at 3-months.

CONCLUSION

BNP levels and 6 MWT have good prognostic utility in ADHF patients, and thus may be beneficial in making therapeutic adjustments and taking precautionary measures in these patients.

Six-minute walk test in healthy British service personnel

INTRODUCTION

The 6 min walk test (6MWT) is a widely used, safe and effective submaximal exercise test. The primary outcome is the distance walked, but additional physiological and patient-reported metrics can be recorded. It is used to assess function and is commonly used within UK Defence Rehabilitation. However, there are no published British military 6MWT data in a non-injured population. This study reports the 6MWT procedure and results from healthy British service personnel.

METHODS

A convenience sample of 46 individuals (male n=40) undertook 95 6MWTs over three study visits throughout a year. They were performed on a 20 m straight-line route, administered by an exercise rehabilitation instructor and preceded by anthropometric measurements (height, weight). Physiological measures (HR, oxygen saturations (SpO2)) and patient-reported measures (Borg shortness of breath (SoB), rate of perceived exertion (RPE) and fatigue) were taken before and after the assessment. Statistical tests were performed between pre-test and post-test measures, and sex and body mass, and concurrent cardiopulmonary exercise tests (CPET) with 6MWT distance.

RESULTS

The mean 6MWT distance was 705.5±86 m; males 709.4±86.9 m and females 685.9±81.9 m (p=0.32), with a median Borg SoB of 1 (IQR: 0-2) and RPE 9 (IQR: 7-11), and a negative correlation between body mass index and 6MWT distance, p=0.007. There were no significant differences between pre-test and post-test measures. Peak workload and VO2 Max correlated weakly with 6MWT distance (0.336, p=0.01 and 0.375, p=0.09, respectively), but submaximal CPET measures did not.

CONCLUSION

These results provide a benchmark for British military 6MWT data to guide clinical and research use. However, a larger dataset is required for validation and normative values.

Prognostic Value of Hemodynamic Gain Index in Patients With Heart Failure With Reduced Ejection Fraction

BACKGROUND

Assessment of functional capacity in patients with heart failure with reduced ejection fraction (HFrEF) is essential for risk stratification, and it traditionally relied on cardiopulmonary exercise testing (CPET)-derived peak oxygen consumption (peak Vo2).

OBJECTIVES

This study sought to investigate the prognostic value of alternative nonmetabolic exercise testing parameters in a contemporary cohort with HFrEF.

METHODS

Medical records of 1,067 consecutive patients with chronic HFrEF who underwent CPET from December 2012 to September 2020 were reviewed for a primary outcome that was a composite of all-cause mortality, left ventricular assist device implantation, and/or heart transplantation. Multivariable Cox regression and log-rank testing were used to determine prognostic values of various exercise testing variables.

RESULTS

The primary outcome was identified in 331 of 954 patients (34.7%) of the HFrEF cohort (median follow-up time, 946 days). After adjustment for demographics, cardiac parameters, and comorbidities, higher hemodynamic gain index (HGI) and peak rate-pressure product (RPP) were associated with greater event-free survival (adjusted HR per doubling: 0.76 and 0.36; 95% CI: 0.67-0.87 and 0.28-0.47; all P < 0.001, respectively). Moreover, HGI (area under the curve [AUC]: 0.69; 95% CI: 0.65-0.72) and peak RPP (AUC: 0.71; 95% CI: 0.68-0.74) were comparable to the standard peak Vo2 (AUC: 0.70; 95% CI: 0.66-0.73; P for comparison = 0.607 and 0.393, respectively) for primary outcome discrimination.

CONCLUSIONS

HGI and peak RPP show good correlation with peak Vo2 in terms of prognostication and outcome discrimination in patients with HFrEF and may serve as suitable alternatives to CPET-derived prognostic variables.

Progress in Cardiac Resynchronisation Therapy and Optimisation

Cardiac resynchronisation therapy (CRT) has become the cornerstone of heart failure (HF) treatment. Despite the obvious benefit from this therapy, an estimated 30% of CRT patients do not respond ("non-responders"). The cause of "non-response" is multi-factorial and includes suboptimal device settings. To optimise CRT settings, echocardiography has been considered the gold standard but has limitations: it is user dependent and consumes time and resources. CRT proprietary algorithms have been developed to perform device optimisation efficiently and with limited resources. In this review, we discuss CRT optimisation including the various adopted proprietary algorithms and conduction system pacing.

Association of remote dielectric sensing and six-minute walk distance among those with severe aortic stenosis

BACKGROUND

Remote dielectric sensing (ReDS) is a novel non-invasive electromagnetic energy-incorporated technology to quantify lung fluid levels. The six-minute walk test is an established method to assess exercise capacity among those with a variety of chronic conditions related to heart and pulmonary diseases. We aimed to understand the association between ReDS value and six-minute walk distance (6MWD) in patients with severe aortic stenosis being evaluated for valve replacement.

METHODS

Patients who were hospitalized to receive trans-catheter aortic valve replacement were prospectively included and simultaneous ReDS and 6MWD measurements were performed on admission. We attempted to correlate 6MWD with ReDS value.

RESULTS

A total of 25 patients (median 85 years, 11 men) were included. Median 6MWD was 168 (133, 244) meters and median ReDS value was 26 % (23 %, 30 %). 6MWD displayed a moderate inverse correlation with ReDS value (r = -0.516, p = 0.008) and significantly distinguished ReDS value ≥30 %, representing mild or greater pulmonary congestion, at a cut-off of 170 m (sensitivity 0.67 and specificity 1.00).

CONCLUSIONS

6MWD had a moderate inverse correlation with ReDS values among candidates for trans-catheter aortic valve replacement, indicating that patients with shorter 6MWD had increased pulmonary congestion as assessed by ReDS system.

Cardiac MRI-based right-to-left ventricular blood pool T2 relaxation times ratio correlates with exercise capacity in patients with chronic heart failure

BACKGROUND

MRI T2 mapping has been proven to be sensitive to the level of blood oxygenation. We hypothesized that impaired exercise capacity in chronic heart failure is associated with a greater difference between right (RV) to left ventricular (LV) blood pool T2 relaxation times due to a higher level of peripheral blood desaturation, compared to patients with preserved exercise capacity and to healthy controls.

METHODS

Patients with chronic heart failure (n = 70) who had undergone both cardiac MRI (CMR) and a 6-min walk test (6MWT) were retrospectively identified. Propensity score matched healthy individuals (n = 35) served as control group. CMR analyses included cine acquisitions and T2 mapping to obtain blood pool T2 relaxation times of the RV and LV. Following common practice, age- and gender-adjusted nominal distances and respective percentiles were calculated for the 6MWT. The relationship between the RV/LV T2 blood pool ratio and the results from 6MWT were evaluated by Spearman's correlation coefficients and regression analyses. Inter-group differences were assessed by independent t-tests and univariate analysis of variance.

RESULTS

The RV/LV T2 ratio moderately correlated with the percentiles of nominal distances in the 6MWT (r = 0.66) while ejection fraction, end-diastolic and end-systolic volumes showed no correlation (r = 0.09, 0.07 and - 0.01, respectively). In addition, there were significant differences in the RV/LV T2 ratio between patients with and without significant post-exercise dyspnea (p = 0.001). Regression analyses showed that RV/LV T2 ratio was an independent predictor of the distance walked and the presence of post-exercise dyspnea (p < 0.001).

CONCLUSION

The proposed RV/LV T2 ratio, obtained by two simple measurements on a routinely acquired four-chamber T2 map, was superior to established parameters of cardiac function to predict exercise capacity and the presence of post-exercise dyspnea in patients with chronic heart failure.

Prognostic Impact of Baseline Six-Minute Walk Distance following Trans-Catheter Aortic Valve Replacement

BACKGROUND

The six-minute walk test is a practical tool for assessing functional capacity in patients with a variety of etiologies including pulmonary disease and heart failure. Six-minute walk distance (6MWD) is associated with mortality and morbidity in patients with a variety of comorbidities. We aimed to assess the prognostic impact of baseline 6MWD in patients with severe aortic stenosis undergoing trans-catheter aortic valve replacement (TAVR).

METHODS

Patients with severe aortic stenosis who underwent a six-minute walk test after index admission and underwent TAVR between 2015 and 2022 were included in this retrospective study. Patients were followed up for two years or until November 2022 following TAVR. The impact of baseline 6MWD on the primary composite outcome, defined as all-cause death and all-cause readmission during the 2-year observation period following index discharge, was assessed.

RESULTS

A total of 299 patients (median age 86 years old, 85 men) were included. They received a 6-min walk test prior to TAVR, underwent successful TAVR procedures, and were discharged alive. The median baseline 6MWD was 204 (143, 282) meters. Shorter baseline 6MWD was associated with higher cumulative incidence of the primary outcome with an adjusted hazard ratio of 0.76 (95% confidence interval 0.58-1.01, p = 0.055) with a cutoff 6MWD of 178 m during the 2-year observation period after index discharge.

CONCLUSIONS

Overall, functional capacity was impaired in the elderly patients with severe aortic stenosis prior to TAVR. Patients with severe aortic stenosis having shorter baseline 6MWD tended to have higher rates of morbidity and mortality after successful TAVR. The clinical implication of aggressive cardiac rehabilitation to improve patients' functional capacity and 6MWD-guided optimal patient selection remain the future concerns.

Independent predictors and equation of six-minute walk test in post-cardiac surgery

BACKGROUND

The six-minute walk test (6MWT) has been used to evaluate postsurgical recovery in cardiac patients. No previous study has compared the 6MWT at follow-up with a baseline, or evaluated the long-term effects of cardiac surgery on post-discharge 6MWT OBJECTIVES: To identify the factors independently associated with 6MWD, and to develop an equation to predict 6MWT at the 4-6-week follow-up after post-cardiac surgery hospital discharge.

METHODS

Patient data of elective coronary artery bypass graft (CABG) or non-CABG surgery patients were retrospectively collected. The 6MWT was performed at hospital discharge and at the 4-6-week follow-up. Available demographic and clinical data of patients were analyzed to determine the independent factors of 6MWT. An equation to predict 6MWT were generated by forward stepwise multiple linear regression analysis.

RESULTS

The data of 275 patients (mean age: 62.20±14.57 years, 64.7% male) were analyzed. The mean 6MWT was 179.14±92.18 m at discharge, and increased to 335.20±115.51 m at the 4-6-week follow-up. The 6MWT at the 4-6-week follow-up was independently correlated with 6MWT at discharge, regular exercise, age, gender, and preoperative New York Heart Association (NYHA) classification.

CONCLUSION

The independent predictors: 6MWT at discharge, regular exercise, age, gender, and NYHA classification were used to generate an equation to predict 6MWT at 4-6 weeks after hospital discharge.

The relationship between six-minute walked distance and health-related quality of life in patients with chronic heart failure

Objectives. To assess the relationship between the six-minute walk test (6MWT) and health-related quality of life (HRQL) in patients with chronic heart failure. Methods. Forty-six patients (37 men and 9 women) with chronic heart failure, mean age 68 (SD 9), NYHA II-III and EF 29 (9) % were included. They performed 6MWT and assessed HRQL using two tools, a Swedish version of the 36-item Short Form (SF-36) and the Minnesota Living with Heart Failure Questionnaire (MLHFQ). This was performed repeatedly during a study period of one year. Results. Patients with a walking distance lower than median experienced a lower HRQL than the higher performing half of the cohort, in four dimensions of the SF-36 and the summary of physical and mental components, but not in the dimensions of MLHFQ. Conclusion. Patients with heart failure with a short walking distance assessed their quality of life as inferior in half of the dimensions in the SF-36 but not in the dimensions measured with the MLHFQ. Thus, different aspects of the symptomatology are uncovered using the 6MWT and the different HRQL tools.

Clinical associations and prognostic implications of 6-minute walk test in rheumatoid arthritis

The clinical associations and prognostic implications of the 6-minute walk test (6MWT) distance in patients with rheumatoid arthritis (RA) is yet to be explored. To identify the clinical features and prognostic implications associated with the 6MWT in patients with RA. Cohort study including 387 RA patients who underwent 6MWT. Regression models (linear and logistic) were built to identify independent predictors of shorter 6MWT distance. Cox proportional models were used to study the association of 6MWT distance with cardiovascular outcomes. Patients were subdivided according to 6MWT tertiles: 126 patients walked > 405 m, 129 walked 345-405 m, and 132 walked < 345 m. Older age (> 55 years), elevated waist circumference, NT-pro BNP > 125 pg/mL, anemia, C-reactive protein ≥ 3 mg/dL, and troponin T ≥ 14 pg/mL were independent predictors of walking shorter distances. Patients walking less than 345 m had higher risk of a subsequent cardiovascular hospitalization or cardiovascular death compared with patients walking 345 m or more (adjusted HR: 2.98, 95%CI: 1.37-6.51, p = 0.006). Older age, abdominal obesity, anemia, cardiac dysfunction, and inflammation were associated with walking shorter distances in patients with RA. Walking less than 345 m in the 6MWT was associated with a poor cardiovascular prognosis. The 6MWT is simple, reproducible, and inexpensive, easily performed in routine practice, and provides important information regarding the patients´ status and outcomes, enabling the monitorization of the therapeutic optimization of the various domains of the RA.

Impacts of Astaxanthin Supplementation on Walking Capacity by Reducing Oxidative Stress in Nursing Home Residents

Oxidative stress is associated with deterioration of endurance and muscle strength, which are mostly accompanied by aging. Astaxanthin supplement has excellent antioxidant activity without any pro-oxidative properties. In this study, we investigated how astaxanthin supplementation affects walking endurance and muscle strength in nursing home residents. Healthy elderly individuals (age: 67 to 94) were divided into two groups: 13 subjects received a daily dose of 24 mg of astaxanthin for 16 weeks (astaxanthin group) and 11 subjects received a placebo (placebo group). These subjects were compared using body component measurements, serum d-ROM levels, the distance of 6-min walking, blood lactate levels after the 6-min walking test, and muscle strength. After supplementation, the levels of d-ROMs and blood lactate after the 6-min walking test in the astaxanthin group significantly decreased compared with the placebo group (p < 0.05). Additionally, the walking distance was significantly higher in the astaxanthin group than in the placebo group (p < 0.05), despite a significant reduction in lactate levels after 6-MWT (p < 0.05). However, no significant intergroup differences were observed in muscle mass and strength. Astaxanthin supplement for 16 weeks is effective to increase the endurance capacity of the elderly. Astaxanthin supplement suppresses d-ROMs at rest and lactic acid production after the 6-min walk test. In contrast, astaxanthin supplement did not show significant intergroup differences in the muscle mass and strength. Therefore, the effect was most likely accompanied by an increase in endurance instead of an increase in muscle strength.

Haemodynamic changes of interatrial shunting devices for heart failure: a systematic review and meta-analysis

AIMS

To assess the efficacy and safety, primarily in relation to the haemodynamic effects, of interatrial shunting devices (ISD) for the treatment of heart failure (HF), we conducted a systematic review and a meta-analysis.

METHODS AND RESULTS

We used the MEDLINE, Cochrane Library, Embase, and PubMed databases to identify clinical studies (published to 4 August 2021) that evaluated the effect of ISD on HF. The primary endpoint was defined as changes in pulmonary capillary wedge pressure (PCWP). Secondary endpoints included (i) other haemodynamic indexes, including cardiac output (CO), right atrial pressure (RAP), and mean pulmonary artery pressure (mPAP) by right heart catheterization, and (ii) change from baseline in 6 min walk distance (6MWD). After a literature search and detailed evaluation, six trials enrolling a total of 203 individuals were included in the quantitative analysis. Pooled analyses showed that after ISD implantation, PCWP decreased by a mean 3.10 mmHg [95% confidence interval (CI) -4.56 to -1.64; I2  = 0%; P < 0.0001]. Overall, CO increased by 0.77 L/min (95% CI 0.02 to 1.52; P = 0.04; I2  = 82%), but there were no significant changes in RAP or mPAP. The mean 6MWD increased by 32.33 m (95% CI 10.74 to 53.92; P = 0.003; I2  = 0) after ISD implantation.

CONCLUSIONS

Interatrial shunting device can effectively reduce PCWP, increase CO and 6MWD, and has no obvious adverse effects on the right heart and pulmonary pressure. Studies with larger sample size and longer follow-up time are needed for further verification.

Diabetes Is the Strongest Predictor of Limited Exercise Capacity in Chronic Heart Failure and Preserved Ejection Fraction (HFpEF)

Background and Aim

Type 2 diabetes mellitus (T2DM) is a known risk factor in patients with heart failure (HF), but its impact on phenotypic presentations remains unclear. This study aimed to prospectively examine the relationship between T2DM and functional exercise capacity, assessed by the 6-min walk test (6-MWT) in chronic HF.

Methods

We studied 344 chronic patients with HF (mean age 61 ± 10 years, 54% female) in whom clinical, biochemical, and anthropometric data were available and all patients underwent an echo-Doppler study and a 6-MWT on the same day. The 6-MWT distance divided the cohort into; Group I: those who managed ≤ 300 m and Group II: those who managed >300 m. Additionally, left ventricular (LV) ejection fraction (EF), estimated using the modified Simpson's method, classified patients into HF with preserved EF (HFpEF) and HF with reduced EF (HFrEF).

Results

The results showed that 111/344 (32%) patients had T2DM, who had a higher prevalence of arterial hypertension (p = 0.004), higher waist/hips ratio (p = 0.041), higher creatinine (p = 0.008) and urea (p = 0.003), lower hemoglobin (p = 0.001), and they achieved shorter 6-MWT distance (p < 0.001) compared with those with no T2DM. Patients with limited exercise (<300 m) had higher prevalence of T2DM (p < 0.001), arterial hypertension (p = 0.004), and atrial fibrillation (p = 0.001), higher waist/hips ratio (p = 0.041), higher glucose level (p < 0.001), lower hemoglobin (p < 0.001), larger left atrium (LA) (p = 0.002), lower lateral mitral annular plane systolic excursion (MAPSE) (p = 0.032), septal MAPSE (p < 0.001), and tricuspid annular plane systolic excursion (TAPSE) (p < 0.001), compared with those performing >300 m. In the cohort as a whole, multivariate analysis, T2DM (p < 0.001), low hemoglobin (p = 0.008), atrial fibrillation (p = 0.014), and reduced septal MAPSE (p = 0.021) independently predicted the limited 6-MWT distance.

In patients with HFpEF, diabetes [6.083 (2.613–14.160), p < 0.001], atrial fibrillation [6.092 (1.769–20.979), p = 0.002], and septal MAPSE [0.063 (0.027–0.184), p = 0.002], independently predicted the reduced 6-MWT, whereas hemoglobin [0.786 (0.624–0.998), p = 0.049] and TAPSE [0.462 (0.214–0.988), p = 0.041] predicted it in patients with HFrEF.

Conclusion

Predictors of exercise intolerance in patients with chronic HF differ according to LV systolic function, demonstrated as EF. T2DM seems the most powerful predictor of limited exercise capacity in patients with HFpEF.

The benefit of exercise rehabilitation guided by 6-minute walk test on lipoprotein-associated phospholipase A2 in patients with coronary heart disease undergoing percutaneous coronary intervention: a prospective randomized controlled study

Background

Lipoprotein-associated phospholipase A2 (Lp-PLA2) has been taken as a biomarker of inflammation in patients with acute coronary diseases. Regular exercise rehabilitation could attenuate inflammation and promote the rehabilitation of coronary heart disease (CHD). The level of Lp-PLA2 is negatively correlated with 6-min walk test (6-MWT). The exercise prescription of appropriate intensity is the basis of exercise rehabilitation. 6-MWT is associated with maximal oxygen consumption, and can be used to determine the intensity of exercise prescription guiding patients how to do exercise rehabilitation. The aim of this study was to observe the benefit of 6-MWT guided exercise rehabilitation on the level of Lp-PLA2 in patients with CHD undergoing percutaneous coronary intervention (PCI).

Methods

We prospectively, consecutively enrolled 100 patients between Dec 2018 and Dec 2020 in the fourth ward of the Department of Cardiology, Yuebei People's Hospital Affiliated to Shantou University. Eligible patients were 1:1 divided into Group A, with no exercise rehabilitation, and Group B, with regular exercise rehabilitation, using random number table method of simple randomization allocation. Clinical data such as general information, the profile of lipids and the level of Lp-PLA2 were collected at baseline and at 12-week follow-up.

Results

There were no statistically significant differences of the percentages of gender, hypertension, type-2 diabetes mellitus (T2DM), the profile of lipids and level of Lp-PLA2 between the groups at baseline (P > 0.05). The level of Lp-PLA2 decreased at 12-week follow-up, moreover, the decline of the Lp-PLA2 level in Group B was more significant than that in Group A (t = 2.875, P = 0.005). Multivariate linear regression analysis indicated that exercise rehabilitation was independently correlated with the level of Lp-PLA2 (β′ = − 0.258, t = − 2.542, P = 0.013).

Conclusion

Exercise rehabilitation for 12 weeks guided by 6-MWT can further reduce the level of LP-PLA2 in patients with CHD undergoing PCI.

Trial registration This trial was registered on the Chinese Clinical Trial Registry: ChiCTR2100048124, registered 3 July 2021- Retrospectively registered. The study protocol adheres to the CONSORT guidelines.

Role of confirmed and potential predictors of an unfavorable outcome in heart failure in everyday clinical practice

Heart failure (HF) is the only cardiovascular disease with an ever increasing incidence. HF, through reduced functional capacity, frequent exacerbations of disease, and repeated hospitalizations, results in poorer quality of life, decreased work productivity, and significantly increased costs of the public health system. The main challenge in the treatment of HF is the availability of reliable prognostic models that would allow patients and doctors to develop realistic expectations about the prognosis and to choose the appropriate therapy and monitoring method. At this moment, there is a lack of universal parameters or scales on the basis of which we could easily capture the moment of deterioration of HF patients' condition. Hence, it is crucial to identify such factors which at the same time will be widely available, cheap, and easy to use. We can find many studies showing different predictors of unfavorable outcome in HF patients: thorough assessment with echocardiography imaging, exercise testing (e.g., 6-min walk test, cardiopulmonary exercise testing), and biomarkers (e.g., N-terminal pro-brain type natriuretic peptide, high-sensitivity troponin T, galectin-3, high-sensitivity C-reactive protein). Some of them are very promising, but more research is needed to create a specific panel on the basis of which we will be able to assess HF patients. At this moment despite identification of many markers of adverse outcomes, clinical decision-making in HF is still predominantly based on a few basic parameters, such as the presence of HF symptoms (NYHA class), left ventricular ejection fraction, and QRS complex duration and morphology.

The Role of 6-Minute Walk Test Guided by Impedance Cardiography in the Rehabilitation Following Knee Arthroplasty: A Randomized Controlled Trial

Objective: To explore the effect of the 6-minute walk test (6MWT) guided by non-invasive cardiac output on the rehabilitation of patients with knee osteoarthritis following artificial total knee arthroplasty.

Methods: About 66 patients with knee osteoarthritis planned to undergo artificial total knee arthroplasty were included from March 2019 to October 2019, and randomly assigned to the intervention group or control group. Under the guidance of a clinical rehabilitation physician, orthopedic physician, and cardiologist, a home rehabilitation exercise program based on 6MWT and non-invasive cardiac output was formulated for patients with knee osteoarthritis. The participants of the intervention group conducted full rehabilitation training supervision and guidance through the WeChat platform to ensure their rehabilitation pieces of training were completed safely and effectively. As for the control group, patients were just given rehabilitation training manuals at the time of discharge and completed the training by themselves.

Results: At 6 months post-operatively, 6-minute walk distance (413.88 ± 44.61 vs. 375.00 ± 40.53 m, P < 0.05), active metabolic equivalent (4.13 ± 0.29 vs. 3.88 ± 0.27, P < 0.05), stroke volume after 6MWT (114.97 ± 12.05 vs. 98.38 ± 16.43 ml, P < 0.05), and cardiac output (11.92 ± 1.68 vs. 9.79 ± 1.82 l/min, P < 0.05) of the intervention group were significantly higher than those of the control group. The symptom evaluation scores of the intervention group were also better than those of the control group.

Conclusions: The multidisciplinary post-operative rehabilitation exercise training program is beneficial to the recovery of lower limb function and the improvement of exercise capacity after knee replacement, and it also helps to improve the non-invasive hemodynamic indicators related to the cardiac function of the patient.

Clinical Trial Registration:http://www.chictr.org.cn/index.aspx.

Impact of physical performance on exercise capacity in older patients with heart failure with reduced and preserved ejection fraction

BACKGROUND

Low physical performance may contribute to reduced exercise capacity in older patients with heart failure (HF). We sought to identify the determinants of exercise capacity out of a plethora of background factors, including measures of physical performance.

METHODS

We performed a post-hoc analysis of a cohort study that included 1205 consecutive older (age ≥ 65 years) hospitalized patients (the median age, 80 years; 57.4% males).

RESULTS

Low physical performance, defined as ≤1.0 m/s for gait speed, ≥12 s for the 5-time chair stand test, or ≤ 9 points for the Short Physical Performance Battery in both sexes, was seen in 83.9% of the cohort. Multivariate regression analysis revealed that each parameter of physical performance (i.e., gait speed, chair stand test, and balance test) was identified as an independent determinant of lower exercise capacity assessed using the 6-min walking distance. In a logistic regression model, low physical performance predicted short (<300 m) 6-min walking distance (adjusted odds ratio 10.28, 95% CI 6.01-17.60, p < 0.001). No interaction was detected between patients with preserved and reduced ejection fraction.

CONCLUSIONS

Low physical performance was prevalent and independently associated with exercise capacity in older patients with HF, irrespective of preserved or reduced ejection fraction.

Sympathetic activation in heart failure with reduced and mildly reduced ejection fraction: the role of aetiology

Aim

While sympathetic overactivity in heart failure (HF) with reduced ejection fraction (HFrEF; EF < 40%) is well‐documented, it is ill‐defined in patients with mildly reduced EF (HFmrEF; EF 40–49%). Furthermore, the significance of ischaemic versus non‐ischaemic aetiology in sympathetic activation is also unclear and has yet to be studied in HF. Our goal was to compare muscle sympathetic nerve activity (MSNA) in HFmrEF and HFrEF patients and in healthy subjects, as well as to elucidate the influence of the underlying disease.

Methods and results

Twenty‐three HFrEF (age 58 ± 10 years), 33 HFmrEF patients (age 61 ± 10 years), including 11 subjects with non‐ischaemic cardiomyopathy in each HF groups and 10 healthy controls (age 55 ± 10 years), were studied. MSNA—detected by peroneal microneurography, continuous arterial pressure, and ECG—was recorded. MSNA frequency (burst/min) and incidence (burst/100 cycles) were calculated. Association with the patients' characteristics were assessed, and aetiology‐based comparisons were performed. Burst frequency demonstrated a significant stepwise increase in both HFmrEF (41 ± 11 burst/min) and HFrEF (58 ± 17 burst/min, P < 0.001) patients as compared with controls (27 ± 9; P < 0.001 for both HF groups). Similarly, burst incidences were 66 ± 17, 82 ± 15, and 36 ± 10 burst/100 cycles in HFmrEF, HFrEF patients, and in healthy controls, respectively (P < 0.001 for all). Burst frequencies in HF patients showed significant correlation with NT‐proBNP levels, and significant inverse correlations with the subjects' mean RR intervals, stroke volumes, pulse pressures, and EF.

Conclusions

Muscle sympathetic nerve activity parameters indicated significant sympathetic activation in both HFmrEF and HFrEF patients as compared with healthy controls with no difference in relation to ischaemic versus non‐ischaemic aetiology.

Four weeks of electromyostimulation improves muscle function and strength in sarcopenic patients: a three-arm parallel randomized trial

BACKGROUND

Sarcopenia, defined as loss of muscle mass, quality, and function, is associated with reduced quality of life and adverse health outcomes including disability and mortality. Electromyostimulation (EMS) has been suggested to attenuate the loss of muscle mass and function in elderly, sedentary individuals. This study aimed to investigate the effects of EMS on muscle strength and function during 4 weeks of inpatient medical rehabilitation.

METHODS

Patients receiving 4 weeks of inpatient medical rehabilitation diagnosed with sarcopenia using bioimpedance analysis were eligible to participate. One hundred and thirty-four patients (55.7 ± 7.9 years, 25.4% female) were randomly assigned to three groups: whole-body (WB) EMS (n = 48): stimulation of major muscle groups (pectoral muscles, latissimus, trapezius, abdominals, upper arm and leg, lower back muscles, gluteal muscles, and thighs); part-body (PB) EMS (n = 42): stimulation of leg muscles including gluteal muscles and thighs; and control group (CG, n = 44). All participants performed six 20 min training sessions including dynamic movements (squats, lunges, biceps curl, chest press, butterfly reverse, reverse lunges, standing diagonal crunches, etc.) with superimposed (WB-, PB-) EMS or without EMS (CG) in addition to the standard rehabilitation programme. Primary outcome variables included muscle function assessed by chair rise test and 6 min walking test as well as muscle strength (isometric grip strength, leg, arm, and back extension).

RESULTS

Primary outcome variables chair rise test and leg extension improved significantly (P = 0.001, η²  = 0.06 and P = 0.008, η²  = 0.06; EMS vs. CG) in that chair rise test results increased in WB-EMS from 5 (4; 7) to 7 (5; 9), in PB-EMS from 5 (5; 7) to 7 (6; 8), and in CG from 6 (4; 7) to 7 (5; 8) repetitions. Knee extension increased in WB-EMS from 692.3 ± 248.6 to 831.7 ± 298.7 N, in PB-EMS from 682.8 ± 257.8 to 790.2 ± 270.2 N, and in CG from 638.5 ± 236.9 to 703.2 ± 218.6 N. No adverse events or side effects occurred.

CONCLUSIONS

We conclude that EMS might be an additional training option to improve muscle function and strength in sarcopenic patients during a 4 week rehabilitation programme. EMS provides greater functional and strength improvements compared with standard treatment with additional potential health benefits for sarcopenic cardiac and orthopaedic patients.

Exercise capacity following ventricular assist device implantation via thoracotomy with outflow cannula anastomosis to the descending aorta

Left ventricular assist device (LVAD) implantation via left lateral thoracotomy with outflow cannula anastomosis to the descending aorta is an alternative technique that avoids anterior mediastinal planes and requires a single incision. This study compares changes in exercise capacity following LVAD implantation with outflow cannula anastomosis to the descending aorta versus ascending aorta. Adult patients who received a continuous flow centrifugal LVAD implantation and completed both pre- and postimplantation cardiopulmonary exercise tests (CPETs) and or 6-minute walk tests (6MWT) were included. Change in CPET parameters (maximum oxygen intake: vO₂ max, oxygen uptake efficiency ratio: OUES, ventilatory efficiency ratio: vE/vCO₂ Slope) and 6MWT distance were compared between ascending and descending aorta anastomosis groups. Ascending and descending aorta anastomosis cohorts included 59 and 14 patients, respectively. Pre- and postimplantation CPETs were performed 63 ± 12 days before and 216 ± 17 days following implantation. The improvement in CPET parameters (vO₂ max, OUES, vE/vCO₂ Slope) or 6MWT distance was not significantly different between the ascending and descending aorta anastomosis groups. This study found no significant difference in the improvement of CPET parameters or 6MWT distance between LVAD implantation via thoracotomy with outflow cannula anastomosis to descending aorta and standard implantation via sternotomy with outflow cannula anastomosis to ascending aorta.

Physical Functioning in Heart Failure With Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is increasingly prevalent, yet interventions and therapies to improve outcomes remain limited. There has been increasing attention towards the impact of comorbidities and physical functioning (PF) on poor clinical outcomes within this population. In this review, we summarize and discuss the literature on PF in HFpEF, its association with clinical and patient-centered outcomes, and future advances in the care of HFpEF with respect to PF. Multiple PF metrics have been demonstrated to provide prognostic value within HFpEF, yet the data are less robust compared with other patient populations, highlighting the need for further investigation. The evaluation and detection of poor PF provides a potential strategy to improve care in HFpEF, and future studies are needed to understand if modulating PF improves clinical and/or patient-reported outcomes. LAY SUMMARY: • Patients with heart failure with preserved ejection fraction (HFpEF) commonly have impaired physical functioning (PF) demonstrated by limitations across a wide range of common PF metrics.• Impaired PF metrics demonstrate prognostic value for both clinical and patient-reported outcomes in HFpEF, making them plausible therapeutic targets to improve outcomes.• Clinical trials are ongoing to investigate novel methods of detecting, monitoring, and improving impaired PF to enhance HFpEF care.Heart failure with preserved ejection fraction (HFpEF) is increasingly prevalent, yet interventions and therapies to improve outcomes remain limited. As such, there has been increasing focus on the impact of physical performance (PF) on clinical and patient-centered outcomes. In this review, we discuss the state of PF in patients with HFpEF by examining the multitude of PF metrics available, their respective strengths and limitations, and their associations with outcomes in HFpEF. We highlight future advances in the care of HFpEF with respect to PF, particularly regarding the evaluation and detection of poor PF.

Functional outcomes with Carillon device over 1 year in patients with functional mitral regurgitation of Grades 2+ to 4+: results from the REDUCE-FMR trial

AIMS

The objective of this study was to compare functional outcomes through 1 year in patients with core-lab verified moderate to severe (Grades 2+ to 4+) functional mitral regurgitation (FMR) treated with the Carillon device or control in the blinded sham-controlled REDUCE-FMR (Carillon Mitral Contour System for Reducing Functional Mitral Regurgitation) study.

METHODS AND RESULTS

The main outcomes of this analysis were the change in 6 min walk test (6MWT) distance, incidence of heart failure hospitalization or death, change in New York Heart Association (NYHA) class, and change in Kansas City Cardiomyopathy Questionnaire (KCCQ) score through 1 year of follow-up. The minimum clinically important difference (MCID) was defined as a ≥30 m increase in 6MWT distance, an NYHA decrease in ≥1 class, and a ≥3 point increase in KCCQ score. The proportion of patients achieving the MCID in each treatment group was compared using Fisher's exact test, and the number needed to treat (NNT) with the Carillon device was calculated. Among 83 patients (62 Carillon and 21 sham), no statistically significant group differences were observed in the baseline characteristics. All outcomes at 1 year numerically favoured the Carillon group, including MCID for the 6MWT distance (59% vs. 23%, P = 0.029; NNT = 2.8), NYHA class (48% vs. 33%, P = 0.38; NNT = 6.9), KCCQ score (69% vs. 47%, P = 0.14; NNT = 4.5), and freedom from heart failure hospitalization or death (60% vs. 48%, P = 0.45; NNT = 8.3).

CONCLUSIONS

REDUCE-FMR was the first blinded sham-controlled trial to report outcomes with percutaneous therapy for the treatment of FMR. Trends towards improvement in mean 6MWT distance, KCCQ score, and NYHA class were observed with the Carillon device. A substantially higher number of patients achieved MCID for all patient-centred outcomes with the Carillon device compared with the sham procedure.

Prognostic impact of 6 min walk test distance in patients with systolic heart failure: insights from the WARCEF trial

AIMS

This study aimed to investigate the impact of baseline 6 min walk test distance (6MWTD) on time to major cardiovascular (CV) events in heart failure with reduced ejection fraction (HFrEF) and its impact in clinically relevant subgroups.

METHODS AND RESULTS

In the WARCEF (Warfarin versus Aspirin in Reduced Cardiac Ejection Fraction) trial, 6MWTD at baseline was available in 2102 HFrEF patients. Median follow-up was 3.4 years. All-cause death and heart failure hospitalization (HFH) exhibited a significant non-linear relationship with 6MWTD (P = 0.023 and 0.032, respectively), whereas a significant association between 6MWTD and CV death was shown in a linear model [hazard ratio (HR) per 10 m increase, 0.989; P = 0.011]. In linear splines with the best cut-off point at 200 m, the positive effect of a longer 6MWTD on all-cause death and HFH was only observed for 6MWTD > 200 m (HR per 10 m increase, 0.987; P = 0.0036 and 0.986; P = 0.0022, respectively). The associations between 6MWTD and CV outcomes were consistent across clinical subgroups; for age, a significant relationship between 6MWTD and HFH was observed in patients ≥60 years (HR per 10 m increase, 0.98; P < 0.001), but not in patients <60 years (HR per 10 m increase, 1.00; P = 0.98; P = 0.02 for the interaction).

CONCLUSIONS

In HFrEF, 6MWTD is independently associated with all-cause death, CV death, and HFH. 6MWTD of 200 m is the best cut-off point for predicting these adverse events. The prognostic impact of 6MWTD for HFH was only observed in older patients.

Six-minute walk test in cardiac rehabilitation

Six-minute walk test (6MWT) is a simple and safe tool for assessing exercise tolerance in  various  categories  of  patients.  Currently,  6MWT  is  used to assess the functional status of a patient and determine the strategy of increasing physical activity, primarily in patients with reduced exercise tolerance and contraindications for cardiopulmonary exercise  test. The basic requirements for the 6MWT are presented, taking into account the factors affecting its  informativeness  and  accuracy,  as  well  as the interpretation of results. The diagnostic and prognostic value of 6MWT in different categories of patients are discussed. The prospects for 6MWT use in cardiac rehabilitation for planning rehabilitation program, prescribing exercises,  determining  the  risk   of   complications,   and   evaluating the effectiveness  are  considered.  The  limitations  of  6MWT  and  ways to overcome it, as well as directions for further research are presented.

Real-Life Multimarker Monitoring in Patients with Heart Failure: Continuous Remote Monitoring of Mobility and Patient-Reported Outcomes as Digital End Points in Future Heart-Failure Trials

Aims

Heart failure (HF) affects approximately 26 million people worldwide. With an aging global population, innovative approaches to HF evaluation and management are needed to cope with the worsening HF epidemic. The aim of the Real-Life Multimarker Monitoring in Patients with Heart Failure (REALIsM-HF) study (NCT03507439) is to evaluate a composite instrument comprising remote, real-time, activity-monitoring devices combined with daily electronic patient-reported outcome (ePRO) items in patients who have been hospitalized for HF and are undergoing standard HF assessment (e.g., 6-min walking distance [6MWD], blood biomarkers, Kansas City Cardiomyopathy Questionnaire [KCCQ], and echocardiography).

Methods

REALIsM-HF is an ongoing, 12-week, observational study enrolling 80-100 patients aged ≥45 years with HF with preserved ejection fraction (HFpEF; EF ≥45%) or reduced EF (HFrEF; EF ≤35%). Statistical analyses will include examining the association between data from wearables (the AVIVO^© mobile patient management patch or VitalPatch^© biosensor, and the DynaPort MoveMonitor^©), daily ePROs, and conventional HF metrics (e.g., serum/plasma biomarkers, 6MWD, KCCQ, and echocardiographic parameters). The feasibility of and patient compliance with at-home devices will be documented, and the data captured for the purpose of establishing reference values in patients with HFpEF or HFrEF will be summarized.

Conclusions

The REALIsM-HF study is to evaluate the longitudinal daily activity profiles of patients with HF and correlate these with changes in serum/plasma biomarker profiles, symptoms, quality of life, and cardiac function and morphology to inform the use of wearable activity monitors for developing novel therapies and managing patients.

Effects of sarcopenia on functional improvement over the first year after cardiac surgery: a cohort study

Background:

Sarcopenia is linked with poor postoperative outcomes.

Aims:

To evaluate the effects of sarcopenia on first-year functional changes after cardiac surgery.

Methods:

In this prospective cohort study, functional changes (physical activity levels in metabolic equivalent hours/week, 6-minute walking distance in metres, and grip strength in kg) from preoperative baseline to 1, 3, 6 and 12 months postoperatively were compared in adult patients with and without sarcopenia undergoing cardiac surgery at a tertiary medical centre. Presurgical sarcopenia was defined as low muscle mass plus either low strength or poor physical performance (i.e. reduced gait speed). Secondary outcomes (length of hospital stay and 1-year mortality) were compared between sarcopenia and non-sarcopenia groups.

Results:

Sarcopenia presented in 27.7% ( n=67) of 242 participants. Participants with sarcopenia were significantly older, predominantly women, and had lower body mass index and higher cardiac surgery risk (measured by the EuroSCORE II) than those without sarcopenia. For both groups, physical activity levels, walking distance and grip strength steadily improved over the year following cardiac surgery. Independent of EuroSCORE II, changes in physical activity levels, walking distance and grip strength did not differ significantly between the sarcopenia and non-sarcopenia groups 1, 3, 6 and 12 months after surgery. Nevertheless, the sarcopenia group had a significantly longer length of hospital stay than the non-sarcopenia group (19.4 vs. 15.3 days; β=2.9, P=0.02) but 1-year mortality (3.4 vs. 3.9% for non-sarcopenia group) was comparable.

Conclusions:

Despite a longer length of hospital stay for the sarcopenia group, sarcopenia was not a restriction for cardiac surgery given their comparable functional improvement and mortality 1 year following surgery.

The baseline speed of 10-m gait predicts ambulatory discharge for hospitalized frail elderly after DOPPO rehabilitation

The discharge of elderly patients from hospital on the basis of their independent gait program (DOPPO) is a new rehabilitation strategy for physically frail hospitalized elderly that aims to recover independent gait and to achieve ambulatory discharge. We retrospectively investigated baseline determinants of physical measures associated closely with the 6-min walking distance (6MWD) after DOPPO. Participants were 137 consecutive elderly inpatients, irrespective of the causative disease (mean age: 82±7 years; 76 women), who had a Short Physical Performance Battery (SPPB) score of less than 12 and low independent walking capacity. The rehabilitation comprised muscle stretching, muscle strengthening, balance training, and endurance exercise, including walking. The exercises were gradually increased until the goal of ambulatory discharge was attained. The SPPB, isometric knee-extension muscle strength (IKEMS), functional reach test (FRT), one-leg stance time (OLST), and the 10-m gait speed (TMGS) were measured, before and after the DOPPO intervention, and their association with the 6MWD was evaluated. All participants achieved ambulatory discharge, requiring on average 35±19 hospital days and 32±18 h of rehabilitation. The SPPB, IKEMS, FRT, OLST, and TMGS improved. The SPPB scores increased from 7.1 at baseline to 9.2 at discharge. Eighty-eight patients completed the 6MWD. The SPPB, IKEMS, FRT, OLST, and TMGS were strongly associated with the 6MWD. Only the baseline TMGS and SPPB predicted the 6MWD, with a cut-off TMGS value of 0.84 m/s providing the best prediction of achieving a distance of more than 300 m on the 6MWD. Thus, the baseline TMGS is the best prediction of the ambulatory outcome after the present DOPPO rehabilitation.

Clinical correlates and outcome associated with changes in 6-minute walking distance in patients with heart failure: findings from the BIOSTAT-CHF study

BACKGROUND

The 6-minute walk test (6MWT) is a simple and inexpensive way of measuring exercise capacity in patients with heart failure (HF) that predicts morbidity and mortality. However, there are few reports from large multicentre cohorts assessing the predictive value of baseline and changing walk distance.

METHODS AND RESULTS

In BIOSTAT-CHF, a 6MWT was performed at baseline (n = 1714) and 9 months (n = 1520). Cox proportional hazards models were used to assess the associations between 6MWT distance and the composite of HF hospitalization and/or death. Median follow-up was 21 months. The median (pct_25-75 ) of the 6MWT distance at baseline was 300 m (200-388 m). Independent predictors of a shorter 6MWT distance included older age, female sex, higher heart rate, New York Heart Association class III/IV, orthopnoea, ischaemic heart disease, a previous stroke, current malignancy, and higher N-terminal pro-B-type natriuretic peptide (all P < 0.05). Patients in the lowest baseline 6MWT tertile (≤ 240 m) were less likely to receive guideline-recommended doses of disease-modifying therapies (P < 0.05). Compared to patients in the highest baseline 6MWT tertile (> 360 m), those in the lowest and middle tertiles had a worse prognosis [adjusted hazard ratio (HR) 1.73, 95% confidence interval (CI) 1.38-2.18]. Patients with a decrease in the distance walked had a worse prognosis (adjusted HR for each 50 m decrease 1.09, 95% CI 1.06-1.12). 6MWT distance was not modified by treatment up-titration nor the 6MWT improved the BIOSTAT-CHF prognostic models.

CONCLUSIONS

The 6-minute walk test distance at baseline and a decline in walking distance were both associated with worse prognosis but did not improve the prognostic models. 6MWT distance was not modified by treatment up-titration and its use for assessing the benefits of pharmacologic treatment up-titration may be limited.

The Importance of the Double Product in the Six-Minute Walk Test to Predict Myocardial Function

Introduction

The Six-Minute Walk Test (6MWT) is a widely used test to measure the physical performance of patients to assess the effectiveness of treatment, to qualify for rehabilitation, and to evaluate its effects..

Aim

This paper focuses on the assessment of the growth of a double product (DP) during the 6MWT and its diagnostic value in the assessment of patients with heart failure.

Material and Methods

The paper has retrospective character. We analyzed medical records of 412 patients hospitalized for cardiac reasons, in whom a 6MWT was performed. The patients were divided into two groups: one with diagnosed heart failure and a control group.

Results

The patients with diagnosed heart failure, compared to the control group, were characterized by a shorter walking distance and greater DP increase at equal walking intervals. After distinguishing the group with the preserved and decreased left ventricle ejection fraction, the value of the DP increase was still higher compared to the control group. The mean DP increase corresponding to one meter of walk was the only one that correlated negatively with the left ventricular ejection fraction.

Conclusion

The assessment of the increase of the DP during the march test seems to be a better parameter reflecting the efficiency of the myocardium from the distance of the march.

Measuring Physical Activity With Implanted Cardiac Devices: A Systematic Review

Background

Physical activity is predictive of cardiovascular outcomes in patients with cardiovascular implantable electronic devices, yet it is not regularly assessed in routine care. Current‐generation cardiovascular implantable electronic devices, however, continuously monitor patient activity through a built‐in accelerometer, which provides new opportunities to remotely assess patient activity, detect changes in clinical status, and incorporate these data in risk stratification models. This review critically examines the literature on device‐measured physical activity (D‐PA), with a focus on identifying methodological issues that may affect interpretation of study results.

Methods and Results

We conducted a systematic review of D‐PA studies published from January 1 1995 to December 30 2017, identifying 29 studies meeting inclusion criteria, 5 of which were validation reports. Few technical details about D‐PA sensors are reported, and procedures for analyzing and interpreting D‐PA data are heterogeneous. Trends in D‐PA over time and associations with clinical outcomes were reported by 22 studies, and in 7 studies, D‐PA was combined with other device parameters in risk stratification models, demonstrating modest‐to‐good sensitivity in predicting acute heart failure decompensation, hospitalization, and mortality.

Conclusions

Current evidence suggests that D‐PA may be useful for assessing physical activity and predicting clinical outcomes in patients with cardiovascular implantable electronic devices when combined with other device parameters. Future work must address challenges related to D‐PA data measurement, interpretation, and generalizability to support expanded clinical applications of this technology.

Comparison of the long-term reproducibility of the walk test and of exercise peak oxygen consumption in patients with preserved exercise capacity

Short-term and long-term reproducibility of the cardiopulmonary (CPX) exercise test have been established. Though short and mid-term reproducibility of the walk test has been ascertained, this was not extensively done for the long-term reproducibility. The aim of the study was to examine the long-term reproducibility of distance walked in an allotted time and to check the stability of the relationship between walked distance and exercise peak VO₂ (pVO₂).

METHODS

Forty six subjects (33 men; 57 ± 14 years), referred for functional capacity assessment, were studied twice by CPX and walking test. On the same day, CPX was performed on a bicycle or a treadmill and walk test in a corridor as required by specific guidelines. We performed a 12-minute walk test and the distance covered in six minutes was systematically taken down. A free time interval of 1.5 hours was observed between the exercise tests. Distance walked in the allotted time and pVO₂ were analysed. Reproducibility was assessed according to Bland and Altman plots and intra-class coefficient correlation (ICC). The relationship between distance ambulated and pVO₂ was analysed by the Spearman coefficient correlation.

RESULTS

The time interval between the two evaluations was 290 ± 10 days. During this meantime, for those subjects having drug treatment, no change was recorded in their regimen. BMI remained stable for the entire studied population (28 ± 5 kg/m²). Minute walked distance was respectively 522 ± 83 and 527 ± 76 m in six minutes, 1033 ± 182 and 1041 ± 153 m in 12 minutes. pVO₂ was 21 ± 7 and 22 ± 7 ml/kg/min (all p = NS). The walk test was reproducible in the long-term, regardless of the modality (6 or 12-minute walk) as shown by the Bland-Altman plots and the high ICC of .89. Spearman's rho coefficient between distance ambulated and pVO₂ was modest and remained stable over time whatever the allotted time: Spearman's r = .54; p = .0011 (1st evaluation) and Spearman's r = .51; p = .0019 (2nd evaluation) between 6-minute distance walked and pVO₂.

CONCLUSIONS

The walking distance in an allotted time seems highly reproducible in the long-term. Its relationship with pVO₂ remains stable over time. It could be of value for repeated assessment of patients' exercise capacity in a first step. Further evaluation in a larger population is needed to confirm our result and its usefulness in clinical practice.

Six-Minute Walk Test for Assessing Physical Functional Capacity in Chronic Heart Failure

PURPOSE OF THE REVIEW

The six-minute walk test (6MWT) is a submaximal exercise test for evaluating physical functional capacity. This review aims to report the research on the use of the 6MWT in chronic heart failure (CHF) that has been published in the past 5 years.

RECENT FINDINGS

The 6MWT distance does not accurately reflect peak VO₂. Minimal clinically important difference in the 6MWT distance, and additional measurements, such as heart rate recovery, can assist in the interpretation of the 6MWT distance, so management decisions can be made. Incorporating mobile apps and information technology in measuring the 6MWT distance extends the usefulness of this simple walk test and improve remote monitoring of patients with CHF. The 6MWT is a useful tool in CHF programs. However, interpretation of the 6MWT distance must be with caution. With the advancement in technology, the 6MWT has the potential to facilitate the monitoring of people living in rural and remote areas.

Physical performance in newly diagnosed hypothyroidism: a pilot study

OBJECTIVE

Hypothyroidism is complicated by neuromuscular symptoms (myalgias, slowness of movements, and tiredness) and signs (easy fatigability and cramps), which may have a negative impact on general well-being and quality of life. In a pilot, prospective, controlled study, we investigated the features of muscle dysfunction in hypothyroidism by disease questionnaire, biochemical measures, and physical performance tests.

MATERIALS AND METHODS

Fifty-seven consecutive patients with newly diagnosed hypothyroidism were enrolled, 27 subclinical (S-Hypo) and 30 overt (O-Hypo). A series of 30 euthyroid subjects, with similar demographic characteristics, served as controls. Patients were administered a short disease questionnaire and underwent laboratory exams and standardized physical tests, both at baseline and after restoration of biochemical euthyroidism.

RESULTS

Compared to euthyroid controls, the O-Hypo group showed significantly higher prevalence of neuromuscular symptoms and significantly higher serum creatine phosphokinase (CPK) levels (p value < 0.0001). S-Hypo had slightly higher CPK levels and prevalence of neuromuscular symptoms than controls. Both S-Hypo and O-Hypo patients performed worse than controls in the six-minute walking test. Differences between patients and controls in handgrip strength test and timed chair standing test failed to reach statistical significance (although a trend was noticeable), possibly due to the small sample size. In O-Hypo, an inverse correlation was found between CPK levels and the handgrip strength test (p value < 0.001). Restoration of euthyroidism was associated with normalization of questionnaire responses, six-minute walking test, as well as serum CPK levels.

CONCLUSION

In addition to neuromuscular symptoms, hypothyroidism is associated with abnormalities of physical performance. The six-minute walking test is the most valuable test to assess this aspect. In the pilot study, levothyroxine therapy could reverse muscle functional abnormalities.

Correlation of 6-min walk test with left ventricular function and quality of life in heart failure due to Chagas disease

OBJECTIVES

To evaluate the correlation of the total distance walked during the six-minute walk test (6MWT) with left ventricular function and quality of life in patients with Chagas Disease (ChD) complicated by heart failure.

METHODS

This is a cross-sectional study of adult patients with ChD and heart failure diagnosed based on Framingham criteria. 6MWT was performed following international guidelines. New York Heart Association functional class, brain natriuretic peptide (BNP) serum levels, echocardiographic parameters and quality of life (SF-36 and MLHFQ questionnaires) were determined and their correlation with the distance covered at the 6MWT was tested.

RESULTS

Forty adult patients (19 male; 60 ± 12 years old) with ChD and heart failure were included in this study. The mean left ventricular ejection fraction was 35 ± 12%. Only two patients (5%) ceased walking before 6 min had elapsed. There were no cardiac events during the test. The average distance covered was 337 ± 105 metres. The distance covered presented a negative correlation with BNP (r = -0.37; P = 0.02), MLHFQ quality-of-life score (r = -0.54; P = 0.002), pulmonary artery systolic pressure (r = -0.42; P = 0.02) and the degree of diastolic dysfunction (r = -0.36; P = 0.03) and mitral regurgitation (r = -0.53; P = 0.0006) and positive correlation with several domains of the SF-36 questionnaire.

CONCLUSIONS

The distance walked during the 6MWT correlates with BNP, quality of life and parameters of left ventricular diastolic function in ChD patients with heart failure. We propose this test to be adopted in endemic areas with limited resources to aid in the identification of patients who need referral for tertiary centres for further evaluation and treatment.

Effect of a 6-month pedometer-based walking intervention on functional capacity in patients with chronic heart failure with reduced (HFrEF) and with preserved (HFpEF) ejection fraction: study protocol for two multicenter randomized controlled trials

Background

Regular physical activity is recommended for patients with chronic heart failure to improve their functional capacity, and walking is a popular, effective, and safe form of physical activity. Pedometers have shown potential to increase the amount of walking across a range of chronic diseases, but it is unknown whether a pedometer-based intervention improves functional capacity and neurohumoral modulation in heart failure patients.

Methods

Two multicenter randomized controlled trials will be conducted in parallel: one in patients with chronic heart failure with reduced ejection fraction (HFrEF), the other in patients with chronic heart failure with preserved ejection fraction (HFpEF). Each trial will consist of a 6-month intervention with an assessment at baseline, at 3 months, at the end of the intervention, and 6 months after completing the intervention. Each trial will aim to include a total of 200 physically inactive participants with chronic heart failure who will be randomly assigned to intervention or control arms. The 6-month intervention will consist of an individualized pedometer-based walking program with weekly step goals, behavioral face-to-face sessions with a physician, and regular telephone calls with a research nurse. The intervention will be based on effective behavioral principles (goal setting, self-monitoring, personalized feedback). The primary outcome is the change in 6-min walk distance at the end of the 6-month intervention. Secondary outcomes include changes in serum biomarkers levels, pulmonary congestion assessed by ultrasound, average daily step count measured by accelerometry, anthropometric measures, symptoms of depression, health-related quality of life, self-efficacy, and MAGGIC risk score.

Discussion

To our knowledge, these are the first studies to evaluate a pedometer-based walking intervention in patients with chronic heart failure with either reduced or preserved ejection fraction. The studies will contribute to a better understanding of physical activity promotion in heart failure patients to inform future physical activity recommendations and heart failure guidelines.

Trial registration The trials are registered in ClinicalTrials.gov, identifiers: NCT03041610, registered 29 January 2017 (HFrEF), NCT03041376, registered 1 February 2017 (HFpEF)

Predictors and Association With Clinical Outcomes of the Changes in Exercise Capacity After Transcatheter Aortic Valve Replacement

BACKGROUND

At present, there are no objective data specifically examining the clinical impact of variations in exercise capacity post-transcatheter aortic valve replacement (TAVR). We describe the changes in exercise capacity between baseline and 6 months post-TAVR, and ascertain factors associated with and clinical implications of a lack of improvement in exercise capacity post-TAVR.

METHODS

A total of 305 patients (mean age, 79±9 years; 44% men; Society of Thoracic Surgeons predicted risk mortality score, 6.7±4.2%) undergoing TAVR completed both baseline and follow-up exercise capacity assessments at 6 months post-TAVR. Exercise capacity was evaluated by the 6-minute walk test (6MWT). Clinical outcomes were compared between patients displaying greater than (n=152; improving group) versus less than (n=153; nonimproving group) the median percentage change in distance walked between baseline and 6-month follow-up examinations. The primary outcome measure was clinical event rates, measured from the 6-month post-TAVR period onward. Further dichotomization according to baseline 6MWT distance (less than versus more than median walking distance, or slow walker versus fast walker) was also assessed.

RESULTS

The mean overall distances walked pre- and post-TAVR (6 months post-TAVR) were 204±119 and 263±116 m, respectively (Δ6MWT=60±106 m), with 219 (72%) patients demonstrating an increase in their walking distance (median percentage increase of the entire population was 20% [interquartile range, 0%-80%]). Factors independently correlated with reduced exercise capacity improvement included a range of baseline clinical characteristics (older age, female sex, chronic obstructive pulmonary disease; P<0.05 for all), periprocedural major or life-threatening bleeding (P=0.009) and new-onset anemia at 6 months post-TAVR (P=0.009). Failure to improve the 6MWT distance by at least 20% was independently associated with all-cause mortality (P=0.002) and cardiovascular death or rehospitalization for cardiovascular causes (P=0.001). Baseline slow walkers who were able to improve the 6MWT distance presented with significantly better outcomes than nonimprovers (P=0.01 for all-cause mortality; P=0.001 for cardiovascular end point).

CONCLUSIONS

Approximately one-third of patients undergoing TAVR did not improve their exercise capacity postprocedure. The lack of functional improvement post-TAVR was predicted by a mix of baseline and periprocedural factors translating into poorer clinical outcomes. These results suggest that systematically implementing exercise capacity assessment pre- and post-TAVR may help to improve patient risk stratification.

End points in heart failure-are we doing it right?

PURPOSE

Heart Failure (HF) continues to be associated with high mortality and morbidity. We attempted to identify the most common end points used in phase 3 clinical trials of heart failure and discuss their merits and demerits.

METHODS

Literature evaluation was done using the databases PubMed and Clinicaltrials.gov from January 2010 to December 2016 to identify randomised clinical trials (RCTs) evaluating the effect of therapeutic drugs on heart failure. Following the literature search, the data on the primary end points were extracted from each of the selected trials. The most recurrent and important end points of Phase III clinical trials for HF over the last six years were identified for further discussion.

RESULTS

From our search, it was observed that the most common end points used in trials with acute heart failure (AHF) were composite end point, dyspnea, CV death and most common end points used in trials with chronic heart failure (CHF) were composite end point, 6 minute walk test (6MWT), CV death or HFH, Vo2 max, all cause mortality, left ventricular ejection fraction (LVEF), and dyspnea.

CONCLUSION

Choosing the appropriate end points is a critical step in the study design that could turn the tide in the beleaguered drug development pipeline of HF, resulting in the right molecule reaching the HF community.

Prognostic indices among hypertensive heart failure patients in Nigeria: the roles of 24-hour Holter electrocardiography and 6-minute walk test

Background

Hypertensive heart failure (HHF) is associated with a poor prognosis. There is paucity of data in Nigeria on prognosis among HHF patients elucidating the role of 24-hour Holter electrocardiogram (ECG) in concert with other risk factors.

Objective

The aim of this study was to determine the prognostic utility of 24-hour Holter ECG, the 6-minute walk test (6-MWT), echocardiography, clinical and laboratory parameters among HHF patients.

Methods

A total of 113 HHF patients were recruited and followed up for 6 months. Thirteen of these patients were lost to follow-up, and as a result only 100 HHF patients were analyzed. All the patients underwent baseline laboratory tests, echocardiography, 24-hour Holter ECG and the 6-MWT. HHF patients were analyzed as “mortality vs alive” and as “events vs no-events” based on the outcome at the end of 6 months. Events was defined as HHF patients who were rehospitalized for heart failure (HF), had prolonged hospital stay or died. No-events group was defined as HHF patients who did not meet the criteria for the events group.

Results

HHF patients in the mortality group (n = 7) had significantly higher serum urea (5.71 ± 2.07 mmol/L vs 3.93 ± 1.45 mmol/L, p = 0.003) than that in those alive. After logistic regression, high serum urea conferred increased mortality risk (p = 0.035). Significant premature ventricular complexes (PVCs) on 24-hour Holter ECG following logistic regression were also significantly higher (p = 0.015) in the mortality group than in the “alive” group (n = 93) at the end of the 6-month follow-up period. The 6-minute walk distance (6-MWD) was least among the HHF patients who died (167.26 m ± 85.24 m). However, following logistic regression, the 6-MWT was not significant (p = 0.777) for predicting adverse outcomes among HHF patients. Patients in the events group (n = 41) had significantly higher New York Heart Association (NYHA) class (p = 0.001), Holter-detected ventricular tachycardia (VT; p = 0.009), Holter-detected atrial fibrillation (AF; p = 0.028) and PVCs (p = 0.017) following logistic regression than those in the no-events group (n = 59).

Conclusion

High NYHA class, elevated serum urea, Holter ECG-detected AF and ventricular arrhythmias are predictive of a poor outcome among HHF patients. The 6-MWT was not a useful prognostic index in this study.

Effects of altitude on effort tolerance in non-acclimatized patients with ischemic left ventricular dysfunction

BACKGROUND

Few studies exist on the effects, in terms of work capacity and safety, of exposure to moderately high altitudes in patients with stable ischemic left ventricular dysfunction. Moreover no data are currently available on the cardiorespiratory response to walks in the mountains.

AIM

The objective of this study is to evaluate the effects of altitude on effort tolerance during walks in the mountains and to determine whether exposure to altitude may be harmful to patients with ischemic left ventricular dysfunction.

METHODS

Forty-five patients with stable chronic ischemic left ventricular dysfunction (ejection fraction=35+/-4%, and peak VO2>/=18/ml/kg per min in a preliminary effort test) were compared to 24 normal subjects. All subjects underwent a series of 6-min walking tests at three different altitudes: 500, 2000 and 2970 m above sea level. Cardiorespiratory response was assessed by a validated portable instrument. The resting arterial PO2 was measured at the three altitudes.

RESULTS

No complications were observed during any tests in either the patients or the healthy controls. Overall, healthy subjects had higher values of 6-min walking test VO2 and walked longer distances in the test than did the patients with left ventricular dysfunction. The mean distances walked in the 6-min walking test were similar at 500 and at 2000 m in both the healthy controls and the patients; at 2970 m, however, the distances decreased in both groups, and more so in the patients (-11+/-3%) than in the controls (-5+/-2%) (P<0.01). VO2 during the 6-min walking test remained stable when the test was carried out at 500 and 2000 m (20.4+/-3.6 versus 19.9+/-4.1 ml/kg per min in patients, and 30.2+/-3.4 versus 29.8+/-4.2 ml/kg per min in the controls; P, NS), but decreased at 2970 m by 13.9+/-3% in patients (P<0.01) and by 6.6+/-2.1% in controls (P<0.01) (patients versus controls, P<0.01). Finally, a similar, significant decrease in arterial PO2 was observed in both groups only at 2970 m (-29%, P<0.01).

CONCLUSION

Patients with stable ischemic left ventricular dysfunction had good tolerance while walking at high altitudes, but showed a moderate decrease in work capacity at 2970 m, which was greater than in normal subjects.

Preoperative Nutrition and Prehabilitation

Enhanced recovery after surgery is the natural evolution of what were previously referred to as fast track programs and seeks to implement a series of interventions to improve and enhance recovery after major surgical procedures. Two important preoperative aspects are nutrition and prehabilitation. Identifying nutritionally deficient patients allows preoperative intervention to optimize their nutritional status. The contribution of cardiopulmonary exercise testing to the evaluation of perioperative risk, subsequent development of a training program, and the use of indices to risk stratify and measure improvement after a training program allow a personalized preoperative program to be developed for each patient.

Could the two-minute step test be an alternative to the six-minute walk test for patients with systolic heart failure?

BACKGROUND

The consequence of exercise intolerance for patients with heart failure is the difficulty climbing stairs. The two-minute step test is a test that reflects the activity of climbing stairs.

DESIGN

The aim of the study design is to evaluate the applicability of the two-minute step test in an assessment of exercise tolerance in patients with heart failure and the association between the six-minute walk test and the two-minute step test.

METHODS

Participants in this study were 168 men with systolic heart failure (New York Heart Association (NYHA) class I-IV). In the study we used the two-minute step test, the six-minute walk test, the cardiopulmonary exercise test and isometric dynamometer armchair.

RESULTS

Patients who performed more steps during the two-minute step test covered a longer distance during the six-minute walk test (r = 0.45). The quadriceps strength was correlated with the two-minute step test and the six-minute walk test (r = 0.61 and r = 0.48). The greater number of steps performed during the two-minute step test was associated with higher values of peak oxygen consumption (r = 0.33), ventilatory response to exercise slope (r = -0.17) and longer time of exercise during the cardiopulmonary exercise test (r = 0.34). Fatigue and leg fatigue were greater after the two-minute step test than the six-minute walk test whereas dyspnoea and blood pressure responses were similar.

CONCLUSION

The two-minute step test is well tolerated by patients with heart failure and may thus be considered as an alternative for the six-minute walk test.

Accuracy and Usability of a Self-Administered 6-Minute Walk Test Smartphone Application

BACKGROUND

The 6-minute walk test (6MWT) independently predicts congestive heart failure severity, death, and heart failure hospitalizations, but must be administered in clinic by qualified staff on a premeasured course. As part of the Health eHeart Study, we sought to develop and validate a self-administered 6MWT mobile application (SA-6MWTapp) for independent use at home by patients.

METHODS AND RESULTS

We performed a validation study of an SA-6MWTapp in 103 participants. In phase 1 (n=52), we developed a distance-estimation algorithm for the SA-6MWTapp by comparing step counts from an Actigraph and measured distance on a premeasured 6MWT course with step counts and estimated distance obtained simultaneously from our SA-6MWTapp (best estimation algorithm, r=0.89 [95% confidence interval 0.78-0.99]). In phase 2, 32 participants (including those with congestive heart failure and pulmonary hypertension) used the SA-6MWTapp independently in clinic, and the distance estimated by the SA-6MWTapp was compared with the measured distance (r=0.83 [95% confidence interval 0.79-0.92]). In phase 3, 19 patients with congestive heart failure and pulmonary hypertension consecutively enrolled from clinic performed 3.2±1 SA-6MWTapp tests per week at home over 2 weeks. Distances estimated from the SA-6MWTapp during home 6MWTs were highly repeatable (coefficient of variation =4.6%) and correlated with in-clinic-measured distance (r=0.88 [95% confidence interval 0.87-0.89]). Usability surveys performed during the second (in-clinic) and third (at-home) phases demonstrated that the SA-6MWTapp was simple and easy to use independently.

CONCLUSIONS

An SA-6MWTapp is easy to use and yields accurate repeatable measurements in the clinic and at home.

Beneficial effects of long-term intravenous iron therapy with ferric carboxymaltose in patients with symptomatic heart failure and iron deficiency†

Aim

The aim of this study was to evaluate the benefits and safety of long-term i.v. iron therapy in iron-deficient patients with heart failure (HF).

Methods and results

CONFIRM-HF was a multi-centre, double-blind, placebo-controlled trial that enrolled 304 ambulatory symptomatic HF patients with left ventricular ejection fraction ≤45%, elevated natriuretic peptides, and iron deficiency (ferritin <100 ng/mL or 100–300 ng/mL if transferrin saturation <20%). Patients were randomized 1 : 1 to treatment with i.v. iron, as ferric carboxymaltose (FCM, n = 152) or placebo (saline, n = 152) for 52 weeks. The primary end-point was the change in 6-min-walk-test (6MWT) distance from baseline to Week 24. Secondary end-points included changes in New York Heart Association (NYHA) class, Patient Global Assessment (PGA), 6MWT distance, health-related quality of life (QoL), Fatigue Score at Weeks 6, 12, 24, 36, and 52 and the effect of FCM on the rate of hospitalization for worsening HF. Treatment with FCM significantly prolonged 6MWT distance at Week 24 (difference FCM vs. placebo: 33 ± 11 m, P = 0.002). The treatment effect of FCM was consistent in all subgroups and was sustained to Week 52 (difference FCM vs. placebo: 36 ± 11 m, P < 0.001). Throughout the study, an improvement in NYHA class, PGA, QoL, and Fatigue Score in patients treated with FCM was detected with statistical significance observed from Week 24 onwards. Treatment with FCM was associated with a significant reduction in the risk of hospitalizations for worsening HF [hazard ratio (95% confidence interval): 0.39 (0.19–0.82), P = 0.009]. The number of deaths (FCM: 12, placebo: 14 deaths) and the incidence of adverse events were comparable between both groups.

Conclusion

Treatment of symptomatic, iron-deficient HF patients with FCM over a 1-year period resulted in sustainable improvement in functional capacity, symptoms, and QoL and may be associated with risk reduction of hospitalization for worsening HF (ClinicalTrials.gov number NCT01453608).

Six-Minute Walk Distance Predicts VO2 (max) in Patients Supported with Continuous Flow Left Ventricular Assist Devices

Background

Six-minute walk distance (6MWD) and maximal oxygen uptake (VO2 max) are used as prognostic tools in patients with heart failure (HF). Whether these tests provide similar information in the LVAD population is not known.

Methods

Eight patients supported with VentrAssist rotary blood pump LVADs, underwent three days of testing that included 6MWD and VO2 max at normal, high or low speeds, generating twenty-four paired results.

Results

The mean 6MWD was 438 (+/- 90 SD) m and the mean VO2 was 14.12 (+/-1.87) ml/kg/min. There was a modest correlation between VO2(max) and 6MWD (r = 0.56 p = 0.004), which improved (r = 0.72 p = 0.002) when patients with higher resting Pro BNP levels and larger left ventricular end diastolic diameters (LVEDD) were excluded.

Conclusions

6MWD is correlated with VO2 (max) in LVAD supported patients, with higher correlations in patients with better underlying cardiac function.

Determinants of distance walked during the six-minute walk test in patients undergoing cardiac surgery at hospital discharge

Introduction

The aim of this study was to identify the determinants of distance walked in six-minute walk test (6MWD) in patients undergoing cardiac surgery at hospital discharge.

Methods

The assessment was performed preoperatively and at discharge. Data from patient records were collected and measurement of the Functional Independence Measure (FIM) and the Nottingham Health Profile (NHP) were performed. The six-minute walk test (6MWT) was performed at discharge. Patients undergoing elective cardiac surgery, coronary artery bypass grafting or valve replacement were eligible. Patients older than 75 years who presented arrhythmia during the protocol, with psychiatric disorders, muscular or neurological disorders were excluded from the study.

Results

Sixty patients (44.26% male, mean age 51.53 ± 13 years) were assessed. In multivariate analysis the following variables were selected: type of surgery (P = 0.001), duration of cardiopulmonary bypass (CPB) (P = 0.001), Functional Independence Measure - FIM (0.004) and body mass index - BMI (0.007) with r = 0.91 and r2 = 0.83 with P < 0.001. The equation derived from multivariate analysis: 6MWD = Surgery (89.42) + CPB (1.60) + MIF (2.79 ) - BMI (7.53) - 127.90.

Conclusion

In this study, the determinants of 6MWD in patients undergoing cardiac surgery were: the type of surgery, CPB time, functional capacity and body mass index.

The effect of metoprolol succinate on the cardiac function of patients with thalassaemia cardiomyopathy: a double-blind randomised study

BACKGROUND

Heart failure is the most common cause of mortality in β-thalassaemia major. However, the management of this disease, apart from chelation therapy, is largely empirical. Therefore, we decided to evaluate the effect of metoprolol succinate on patients with thalassaemia cardiomyopathy (TCM).

MATERIALS AND METHODS

In this clinical trial, 45 patients with TCM were randomised to receive either metoprolol (n=26) or placebo (n=19). Echocardiography and a 6 min walk test were performed at baseline and repeated after 6 months and the values compared.

RESULTS

In the metoprolol group, left ventricular ejection fraction (LVEF) rose from 38.65% to 42.84% (p<0.001), while it decreased in the placebo group from 37.89% to 35.84% (p=0.01); the difference between the two groups was significant (p<0.001). Left ventricular (LV) mass in the metoprolol group decreased from 154.31 to 144.26 g (p=0.02), while in the placebo group it increased from 174.32 to 200.15 g (p=0.68); the difference between the two groups was significant (p<0.001). End systolic volume (ESV) decreased in the metoprolol group from 42.19 to 36.73 cm(3) (p<0.001) but increased from 47.37 to 57.42 cm(3) in the placebo group (p=0.144); the difference between the groups was significant (p<0.001). No differences in exercise capacity or pulmonary capillary wedge pressure were seen between the two groups (p=0.268 and p=0.535, respectively).

CONCLUSIONS

Metoprolol succinate as a β-blocker may have the potential to significantly improve systolic function in patients with TCM and reverse LV remodelling to the same extent as in other types of cardiomyopathy.

TRIAL REGISTRATION NUMBER

NCT01863173.